scholarly journals A New Approach to Determine the Critical Path in Stochastic Activity Network

2014 ◽  
Vol 2014 ◽  
pp. 1-13
Author(s):  
Weng-Ming Chu ◽  
Koan-Yuh Chang ◽  
Chien-Yu Lu ◽  
Chang-Hung Hsu ◽  
Chien-Hung Liu ◽  
...  
Keyword(s):  
Monte Carlo Simulation ◽  
Path Dependence ◽  
Critical Path ◽  
Stochastic Networks ◽  
Stochastic Network ◽  
New Approach ◽  
Path Index ◽  
Tracing Algorithm ◽  
Selection Of

The determination of the critical path (CP) in stochastic networks is difficult. It is partly due to the randomness of path durations and partly due to the probability issue of the selection of the critical path in the network. What we are confronted with is not only the complexity among random variables but also the problem of path dependence of the network. Besides, we found that CP is not necessarily the longest (or shortest) path in the network, which was a conventional assumption in use. The Program Evaluation and Review Technique (PERT) and Critical Path Index (CPI) approaches are not able to deal with this problem efficiently. In this study, we give a new definition on the CP in stochastic network and propose a modified label-correcting tracing algorithm (M-LCTA) to solve it. Based on the numerical results, compared with Monte Carlo simulation (MCS), the proposed approach can accurately determine the CP in stochastic networks.

scholarly journals Increasing Project Effectiveness by Combining the FMEA Method Results and the Costs of Quality (Based on the Example of an Employee Relationship Management Project)

2021 ◽  
Vol 13 (1) ◽  
pp. 26-68
Author(s):  
Anna Lipka ◽  
Agnieszka Giszterowicz
Keyword(s):  
Success Factors ◽  
Critical Path ◽  
Relationship Management ◽  
Value Added ◽  
Economic Implications ◽  
Employee Relationship ◽  
Management Project ◽  
Fmea Method ◽  
Selection Of

Abstract Objective: This article presents a project focused on the stabilization of employment in a multi-generational organization in the scope of human resources –specifically, employee relationship management. Methodology: The type of project was evaluated by taking into account different typological criteria. The employee generations were defined by providing time ranges based on dates of birth. All important project stages were presented according to the newest PMI 2017 methodology, with particular attention to the selection of the model of the project team and the division of tasks within the team. The critical path method was used in the description of the course of project activities. Findings: The method of determination of project success factors was specified. Value Added: In accordance with the title of the article, it was, however, shown how one can combine the identification of the level of project risk (using failure mode and effects analysis – FMEA) and the costs of quality to increase the project effectiveness. Recommendations: Projects of this type are important in these organizations where the risk of loyalty is high, which leads to negative economic implications. The advantages from such projects can, however, affect more than the employer.

scholarly journals Selection of Satellite Image Series for the Determination of Forest Pathology Dynamics Taking Into Account Cloud Coverage and Image Distortions Based on the Data Obtained from the Key Point Detector

2019 ◽  
Author(s):  
Евгений Трубаков ◽  
Evgeniy Trubakov ◽  
Андрей Трубаков ◽  
Andrey Trubakov ◽  
Дмитрий Коростелёв ◽  
...  
Keyword(s):  
Satellite Image ◽  
Forest Pathology ◽  
Acceptable Result ◽  
New Approach ◽  
Cloud Coverage ◽  
Point Detector ◽  
Automated Methods ◽  
Selection Of

Remote sensing of the earth and monitoring of various phenomena have been and still remain an important task for solving various problems. One of them is the forest pathology dynamics determining. Assuming its dependence on various factors forest pathology can be either short-term or long-term. Sometimes it is necessary to analyze satellite images within a period of several years in order to determine the dynamics of forest pathology. So it is connected with some special aspects and makes such analysis in manual mode impossible. At the same time automated methods face the problem of identifying a series of suitable images even though they are not covered by clouds, shadows, turbulence and other distortions. Classical methods of nebulosity determination based either on neural network or decision functions do not always give an acceptable result, because the cloud coverage by itself can be either of cirrus intortus type or insignificant within the image, but in case of cloudiness it can be the reason for wrong analysis of the area under examination. The article proposes a new approach for the analysis and selection of images based on key point detectors connected neither with cloudiness determination nor distorted area identification, but with the extraction of suitable images eliminating those that by their characteristics are unfit for forest pathology determination. Experiments have shown that the accuracy of this approach is higher than of currently used method in GIS, which is based on cloud detector.

Automatic inference on stable robotic assembly sequences based upon the evaluation of base assembly motion instability

Robotica ◽  
1993 ◽  
Vol 11 (4) ◽  
pp. 351-362 ◽  
Author(s):  
D.Y. Cho ◽  
C.K. Shinf ◽  
H.S. Chot
Keyword(s):  
Robotic Assembly ◽  
Fixture Design ◽  
Assembly Sequence ◽  
Inference Method ◽  
New Approach ◽  
Assembly Sequences ◽  
Crucial Information ◽  
Part Motion ◽  
Selection Of

SUMMARYThe consideration of part motion instability is crucial to the determination of assembly sequence since this affects the complexity of fixtures and dexterity of robots. This paper presents a new approach to the inference of robotic assembly sequences, taking into consideration the instability of base assembly motions. Based upon the evaluation of motion instability, the method generates stable assembly sequences by use of the precedence constraint inference method previously developed by the authors. An example assembly of a 10-part electrical relay is given to illustrate the concepts and procedure of the proposed scheme. The results show that the proposed method can be effectively utilized to generate stable assembly sequences, thus providing crucial information on the fixture design and selection of types of assembly robots.

Reliability assessment of stochastic networks with ER connectivity and ER dependency

2021 ◽  
pp. 1748006X2110019
Author(s):  
Heping Jia ◽  
Rui Peng ◽  
Dunnan Liu ◽  
Yanbin Li ◽  
Yi Ding
Keyword(s):  
Monte Carlo Simulation ◽  
Probability Distributions ◽  
Reliability Assessment ◽  
Reliability Evaluation ◽  
Stochastic Networks ◽  
Evaluation Framework ◽  
Stochastic Network ◽  
Time To Failure ◽  
Numerical Examples ◽  
Mdd Method

In stochastic networks, nodes usually function dependently and interact with other nodes through connectivity links or dependency links. In this paper, the model for stochastic networks considering sub-networks with connectivity and dependency links of Erdös-Rényi (ER) topology is proposed, which is defined as networks with arbitrary pair of nodes randomly connected/depended by a constant probability. The reliability evaluation framework for the proposed networks is developed, where both of the extended multi-valued decision diagram (MDD) method and Monte Carlo simulation (MCS) are involved. The MDD method is proposed to assess the reliability of deterministic stochastic networks with ER connectivity and dependency, where arbitrary time to failure distributions of nodes are allowed. Based on the reliability evaluation for a stochastic network with a deterministic structure, the MCS is employed to achieve the reliability analysis of corresponding stochastic networks. Numerical examples are presented to demonstrate the proposed stochastic network model and reliability evaluation framework, where the probability distributions for the reliability of stochastic networks are provided.

Joint Positions and Robot Stability of the Omnidirectional Crawling Quadruped Robot

1999 ◽  
Vol 11 (6) ◽  
pp. 510-517 ◽  
Author(s):  
Xuedong Chen ◽  
◽  
Keigo Watanabe ◽  
Kiyotaka Izumi ◽  
◽  
...  
Keyword(s):  
Kinematic Chain ◽  
Quadruped Robot ◽  
Robot Kinematics ◽  
Stable Range ◽  
New Approach ◽  
Foot Placement ◽  
Quadruped Robots ◽  
Selection Of ◽  
Stable Area

Determination of joint positions, judgment of robot stability, and selection of the consequential swing leg are keys to crawling control for quadruped robots. We derive an efficient way to obtain actuation variables of joint positions to satisfy the gait for quadruped robots. By defining the statically stable area for foot placement, a new approach on analysis of robot stability is presented. Unlike conventionally, we avoid solving complicated direct robot kinematics as an overall kinematic chain and simultaneously show information on robot stability and the stable range of foot placement. Effectiveness is shown in practical crawling experiments.

scholarly journals Complexation processes in “PbCl2-N2H4CS” aqueous solutions during deposition of lead sulphide films

2021 ◽  
Vol 23 (4) ◽  
pp. 543-547
Author(s):  
Victor N. Semenov ◽  
Vitaly V. Volkov ◽  
Natalia V. Pereslytskikh
Keyword(s):  
Aqueous Solutions ◽  
Coordination Compounds ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Lead Chloride ◽  
Lead Sulphide ◽  
New Approach ◽  
Complex Forms ◽  
Selection Of

In this study, we proposed a new approach to assessing the processes of complexation in aqueous solutions using the example of the interaction of lead chloride with thiourea. The goal of this study was the investigation of processes of complexation in “PbCl2-N2H4CS” aqueous solutions and determination of the regions of dominance of thiourea coordination compounds, which are precursors during the deposition of lead sulphide films.Based on the diagrams and cross section lines of equal fractions constructed in three-dimensional space, the regions of dominance of all complex forms existing in the studied solution were found. Such a graphic image is the most informative, since it allows selection of the concentration ranges of the predominance of certain coordination compounds, especially thiourea complexes, which are precursors during the deposition of lead sulphide films. It was shown that an increase in the concentration of N2H4CS led to an increase in the total fraction of thiourea complexes: for a twofold excess of N2H4CS its fraction was 0.25, for a threefold excess it was 0.35, for a fourfold excess it was 0.5, for a fivefold excess it was 0.7.

Determination of Stoichiometry of GaAs Component in (Gaas)Ge Epitaxially Grown Thin Films by Electron Microprobe X-Ray Analysis

1990 ◽  
Vol 48 (2) ◽  
pp. 264-265
Author(s):  
D. R. Liu ◽  
S. S. Shinozaki ◽  
R. J. Baird
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Compound Semiconductors ◽  
Energy Dispersive Analysis ◽  
X Ray ◽  
Metastable Alloys ◽  
Lower Voltage

The epitaxially grown (GaAs)Ge thin film has been arousing much interest because it is one of metastable alloys of III-V compound semiconductors with germanium and a possible candidate in optoelectronic applications. It is important to be able to accurately determine the composition of the film, particularly whether or not the GaAs component is in stoichiometry, but x-ray energy dispersive analysis (EDS) cannot meet this need. The thickness of the film is usually about 0.5-1.5 μm. If Kα peaks are used for quantification, the accelerating voltage must be more than 10 kV in order for these peaks to be excited. Under this voltage, the generation depth of x-ray photons approaches 1 μm, as evidenced by a Monte Carlo simulation and actual x-ray intensity measurement as discussed below. If a lower voltage is used to reduce the generation depth, their L peaks have to be used. But these L peaks actually are merged as one big hump simply because the atomic numbers of these three elements are relatively small and close together, and the EDS energy resolution is limited.

The Dudley Lee Case: A new approach to factual causation and its implications for transformative jurisprudence

2017 ◽  
Vol 30 (1) ◽  
pp. 273-289
Author(s):  
Anmari Meerkotter
Keyword(s):  
Case Note ◽  
Constitutional Court ◽  
Recent Contribution ◽  
New Approach ◽  
State Accountability ◽  
The Law ◽  
Transformative Impact ◽  
Constitutional Jurisprudence ◽  
Law Of Delict

The Constitutional Court (CC) judgment of Lee v Minister of Correction Services 2013 2SA 144 (CC) is a recent contribution to transformative constitutional jurisprudence in the field of the law of delict. This matter turned on the issue of factual causation in the context of wrongful and negligent systemic omissions by the state. In this case note, I explore the law relating to this element of delictual liability with specific regard to the traditional test for factual causation – the conditio sine qua non (‘but-for’) test. In particular, I note the problems occasioned by formalistic adherence to this test in the context of systemic state omissions as evidenced by the SCA judgment in the same matter. I also consider the manner in which English courts have addressed this problem. Thereafter, I analyse the CC’s broader approach to the determination of factual causation as one based on common sense and justice. I argue that this approach endorses a break from a formalistic application of the test and constitutes a step towards an approach which resonates with the foundational constitutional values of freedom, dignity and equality. Furthermore, it presents an appropriate solution to the problems associated with factual causation where systemic omissions are concerned. I then consider the transformative impact of the Lee judgment. In particular, I argue that the broader enquiry favoured by the CC facilitates the realisation of constitutionally guaranteed state accountability, and amounts to an extension of the existing norm of accountability jurisprudence. Hence, I contend that the judgment presents a further effort by the Constitutional Court to effect wholesale the constitutionalisation of the law of delict, as well as a vindicatory tool to be used by litigants who have been adversely affected by systemic state omissions.

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